JPH09212628A - Image scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an image contrast from being declined and to substantially improve the read accuracy of color images and image quality. SOLUTION: A lamp 10 and a light source lens 14 are disposed to the inner side part of the opening part of a main body case 2 so as to be turned to the opening part 3. On the opposite side end part of the opening part 3 inside the main body case 2, a CCD sensor 16 for receiving light made to irradiate a prescribed original arranged near the opening part 3 from the lamp 10 through the light source lens 14 and reflected by the original through a lens unit 17 and reading the image of the original is disposed. The opening part 3 is formed in a length dimension capable of irradiating only a range required for reading the original with the light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner, and more particularly to an image scanner which reads an image by irradiating a desired document with light and reading the reflected light with a CCD sensor.

[0002]

2. Description of the Related Art Conventionally, an image scanner has been widely used which reads an image by irradiating a desired document with light and reading the reflected light.

FIG. 3 shows such a conventional image scanner. The image scanner 31 has a main body case 32 having a rectangular box shape, and one end face in the longitudinal direction of the main body case 32. Has a substantially rectangular opening 33 facing a predetermined document (not shown) from which an image is read. The opening 33 has a length dimension that extends to almost both sides of the main body case 32,
In the inner portion of the opening 33 of the main body case 32,
The holding plate 34 is integrally formed so as to project inward. Further, a cylindrical lamp 35 is disposed inside each of the holding plates 34, and when the lamp 35 is turned on, light emitted from the lamp 35 is transmitted through a light source lens (not shown) to the main body case. Irradiation is performed to the outside from the opening 33 of 32, and the document placed near the opening 33 is irradiated.

A CC for image reading is provided inside the main body case 32 at an end opposite to the opening 33.
A D sensor 36 is provided, and between the opening 33 inside the main body case 32 and the CCD sensor 36,
A cylindrical lens unit 37 is arranged.

In the conventional image scanner 31 described above, a desired document is set near the opening 33 of the image scanner 31, and in this state, the image scanner 31 or the document is moved relatively to each other. By turning on the lamp 35, the light emitted from the lamp 35 is emitted from the opening 33 to the document through the light source lens. Then, the light reflected by the original document is again made incident on the inside of the main body case 32 through the opening 33, and the CCD sensor 3 through the lens unit 37.
The image sensor 6 receives the light, and the CCD sensor 36 reads the image information of the document.

[0006]

However, in the above-mentioned conventional image scanner 31, the opening 33 has a length dimension reaching almost both sides of the main body case 32, so that the light of the lamp 35 is spread over a wide range of the document. By irradiating the document with light, it is possible to uniformly irradiate the document with the light. Therefore, when the light emitted from the lamp 35 is reflected by the document, the document is read from the actual reading range. The reflected light from the portion other than the reading range of the original becomes large with respect to the reflected light. Therefore, if all of the reflected light is incident on the lens unit 37 and is received by the CCD sensor 36, it is outside the reading range of the original. There is a problem that the contrast of the original image is lowered due to the influence of the reflected light, and the reading accuracy is remarkably lowered.

Conventionally, since the image scanner 31 is of a system that binarizes an image of a document and reads it as a monochrome image, even if the image contrast is somewhat poor, there is no problem. In this case, it has become possible to obtain color image information by reading an image of a document in multi-value gradations such as 256 gradations. As described above, unnecessary reflected light is irradiated to form an image. If the contrast is lowered, the color image cannot be read with high accuracy, and the quality of the read image is deteriorated.

The present invention has been made in view of the above points, and an object of the present invention is to provide an image scanner capable of preventing a decrease in image contrast and significantly improving the reading accuracy and image quality of a color image. It is a thing.

[0009]

In order to achieve the above object, an image scanner according to the invention of claim 1 has an opening formed on one end surface of the main body case, and an inner portion of the opening of the main body case. A lamp and a light source lens are arranged so as to be directed to the opening, and the lamp and the light source lens are located inside the main body case, at an end opposite to the opening, and in the vicinity of the opening from the lamp through the light source lens. An image scanner comprising a CCD sensor for irradiating a predetermined document placed on the document and receiving light reflected by the document through a lens unit to read an image of the document. Is formed in a length dimension such that light can be irradiated only in the range necessary for reading the original.

The invention according to claim 2 is characterized in that the length of the opening is set to be about twice as long as the reading range of the original.

According to the image scanner of the present invention, the length dimension such that the opening can be irradiated with light only in the range necessary for reading the original, that is, about twice the reading range of the original. Since it is formed so as to be the size of the original, when the light emitted from the lamp is reflected by the original as compared with the case where the original is irradiated with light over a wide range as in the past, The reflected light from the part other than the reading range of the original can be reduced with respect to the reflected light from the reading range, and the extra reflected light outside the reading range from the original is received by the CCD sensor via the lens unit. You can definitely reduce the
Only the reflected light near the reading range from the original can be received by the CCD sensor via the lens unit. As a result, it is possible to prevent the influence of reflected light other than the reading range of the original document and significantly improve the image contrast.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 show an embodiment of an image scanner according to the present invention. In this embodiment, the image scanner 1 has a main body case 2 having a rectangular box shape. An opening 3 having a quadrangular shape is formed on one end surface in the longitudinal direction of the main body case 2 so as to face a predetermined document (not shown) for reading an image. Further, the opening 3 is formed so that its width dimension reaches the both side portions of the main body case 2, but the opening 3 irradiates light only in a range necessary for reading the original. It is formed in such a length dimension that it can be made. In the present embodiment, the length dimension of the opening 3 is formed to be about twice the length of the reading range A.

In addition, holding plates 4 and 4 extending along both side surfaces of the body case 2 are integrally formed on the inner portion of the opening 3 of the body case 2 so as to project inward. Each of the holding plates 4 has an inner wall 5 formed so that its inner edge extends in the direction of the opening 3.
have. A concave lamp accommodating portion 6 having an opening toward the opening 3 is formed between the inner wall 5 of the holding plate 4 and the inner side surface of the main body case 2. On the inner surface of the inner wall 5 of the plate 4 and the inner surface of the main body case 2, a lamp locking recess 7 and a lens locking recess 8 located on the opening side of the lamp housing 6 with respect to the lamp locking recess 7 are formed. Has been done. further,
The holding plate 4 is formed with a slit 9 extending along the side surface of the body case 2.

A cylindrical lamp 10 is disposed inside the lamp accommodating portion 6, and the lamp 10 is provided inside the lamp accommodating portion 6 on the outer peripheral surface of the lamp 10. A fixing plate 11 having an arcuate cross-sectional shape for fixing is attached. Further, locking projections 12 are formed on both sides of the outer peripheral surface of the fixing plate 11. By engaging the locking projections 12 with the lamp locking recesses 7, the lamp 10 is housed in the lamp. It is designed to be fixed to the portion 6. Further, terminals 13 connected to both ends of the lamp 10 are drawn out from the slit 9 into the main body case 2, and the terminals 13 are formed on the inner side surface of the main body case 2 of the holding plate 4. Is electrically connected to a wiring board (not shown) arranged in the.

Further, a light source lens 14 having an arcuate cross-section is arranged in the opening portion of the lamp housing portion 6 so that the arcuate portion projects from the opening portion, and both sides of the light source lens 14 are arranged. A locking claw 15 is formed on the edge. The light source lens 14 is fixed by engaging the locking claws 15 with the lens locking recesses 8.

Then, by energizing each of the lamps 10 and turning on the lamps 10, the light emitted from the lamps 10 is radiated to the outside from the opening 3 of the main body case 2 through the light source lens 14. The document placed in the vicinity of the opening 3 is irradiated with the light.

A CCD sensor 16 for image reading having a resolution of about 1/600 inch, for example, is mounted on a substrate (not shown) at the end inside the main body case 2 opposite to the opening 3. A cylindrical lens unit 17 is disposed between the opening 3 and the CCD sensor 16 inside the main body case 2. The lens unit 17 has a light entering portion 18 for entering the light emitted from the lamp 10 and reflected by the document.
And a light emitting section 19 for emitting this light to the CCD sensor 16, respectively.
The light incident from the light incident unit 18 is introduced into the inside of the C
A plurality of imaging lenses 20 for focusing so as to form an image on the CD sensor 16 are arranged at predetermined intervals.

Next, the operation of the present embodiment will be described.

In the present embodiment, first, a desired document is placed near the opening 3 of the image scanner 1,
In this state, each of the lamps 10 is turned on while moving the image scanner 1 or the document relatively.
As a result, the light emitted from the lamp 10 is emitted from the opening 3 to the original through the light source lens 14, and the light reflected by the original enters the inside of the case body again from the opening 3. Then, the light enters the light entering portion 18 of the lens unit 17 through the spaces between the holding plates 4.

The light incident on the lens unit 17 is imaged by the imaging lens 20 of the lens unit 17 and emitted from the light emitting portion 19 to be the CCD sensor 16.
The CCD sensor 16 reads the image information of the document.

The image information read in this way is output to an image control circuit (not shown) composed of, for example, a CPU, a memory, and the like, and by this image control circuit, for example,
The image is displayed on a CRT based on the image information to perform image processing, or printing based on the image information is performed.

Therefore, in this embodiment, since the length of the opening 3 is formed to be about twice as long as the reading range A of the document, the document can be formed as in the conventional case. In contrast to the case where the light emitted from the lamp 10 is reflected by the document, the reading range A of the document is compared with the reflected light from the actual reading range A of the document, as compared with the case where the light is emitted over a wide range. It is possible to reduce the reflected light from the portion other than the surrounding area, and reliably reduce the unnecessary reflected light other than the reading range A from the original document to be received by the CCD sensor 16 via the lens unit 17. Therefore, only the reflected light in the vicinity of the reading range A from the document can be transmitted via the lens unit 17 to the CCD sensor 16
Can be made to receive light.

As a result, it is possible to prevent the influence of the reflected light other than the reading range A of the manuscript and to remarkably improve the image contrast. Therefore, in reading a color image in recent years, for example, the 256th floor. It is possible to read with multi-value gradation such as tones with high accuracy, and it is possible to improve the quality of the read image.

The present invention is not limited to the above-described embodiment, but various modifications can be made if necessary.

[0026]

As described above, in the image scanner according to the present invention, the opening allows the light to be radiated only to the range necessary for reading the original document. Compared to the case of irradiating a wide area with light, the reflected light from the part other than the original reading range can be reduced compared to the reflected light from the actual reading range of the original. It is possible to reliably reduce that the unnecessary reflected light of the above is received by the CCD sensor via the lens unit, and only the reflected light in the vicinity of the reading range from the document is received by the CCD sensor via the lens unit. You can As a result, the image contrast can be remarkably improved, and in the recent color image reading, multi-value gradation reading can be performed with high accuracy, and the quality of the read image can be improved. Play.

[Brief description of drawings]

FIG. 1 is a half sectional side view showing an embodiment of an image scanner of the present invention.

FIG. 2 is a half sectional plan view of the image scanner of FIG.

FIG. 3 is a half cross-sectional side view showing a conventional image scanner.

[Explanation of symbols]

 1 Image Scanner 2 Main Body Case 3 Opening 4 Holding Plate 5 Inner Wall 10 Lamp 14 Light Source Lens 16 CCD Sensor 17 Lens Unit A Reading Range

Claims (2)

[Claims] 1. An opening is formed in one end surface of a main body case, and a lamp and a light source lens are arranged inside the opening of the main body case so as to be directed to the opening. At the end opposite to the opening, a light is emitted from the lamp through the light source lens to a predetermined document arranged in the vicinity of the opening, and the light reflected by the document is received through the lens unit. And an image scanner provided with a CCD sensor for reading an image of the original, and having a length dimension such that the opening can be irradiated with light only in a range necessary for reading the original. An image scanner characterized by being formed on. 2. The image scanner according to claim 1, wherein the length of the opening is about twice as long as the reading range of the original.